Method and system for transmitting route information

ABSTRACT

An object of the invention is to provide a route information transmitting method for transmitting a recommended route or a guided route to a receiving side accurately in as small a volume of data as possible. In the route information transmitting method of the invention, a transmitting side provides the receiving side which requests information on a route with compressed data obtained by performing an arithmetic treatment on position data of a plurality of points aligned along a route so as to convert the position data into statistically biased data and variable length coding the data so converted. The receiving side decodes the compressed data so as to restore the position data to thereby identify the route through a map matching. Due to this, the route information can be transmitted accurately in a small volume of data.

TECHNICAL FIELD

The present invention relates to a route information transmission methodfor transmitting a route to a destination or the like to a receiver sideand a system for performing the method, and more particularly to methodand system for transmitting route information accurately with as small adata volume as possible.

BACKGROUND ART

Conventionally, there have been known vehicular navigation systemsincluding a GPS receiver and a digital map in which when a destinationis set, a recommended traveling route from a current point to thedestination is calculated and is then displayed. Furthermore, there havebeen known systems in which a current point and a destination aretransmitted from an in-vehicle car navigation system to an informationcenter, a recommended route is calculated by adding traffic conditionsat the information center, and the route so calculated is then providedfor the in-vehicle car navigation system.

In addition, on one hand, in most of the conventional vehicularnavigation systems, in order to perform an efficient andeasy-to-understand route guidance while avoiding narrow roads andcomplicatedly routed roads, roads for use for route guidance are limitedto, for example, roads equal to or wider than prefectural roads(prefectural roads, national roads, toll roads and the like) and roadsof 5.5 m or wider. Due to this, in the event that a final destination isoff a road for use for route guidance, while a recommended travelingroad to a peripheral point to the final destination is calculated anddisplayed, there may occur a case where a route from the peripheralpoint to the final destination is not displayed.

With a view to improving such a drawback, a patent document No. 1(JP-A-9-178499) discloses a system in which a vehicular navigationsystem sends information regarding a current point and a finaldestination to an information center, so that the vehicular navigationsystem obtains route information from a peripheral point to the finaldestination to the destination. In this system, the information centerestimates, based on the information so received, a peripheral point tothe destination which the vehicular navigation system can search,calculates a route reaching from the peripheral point to the finaldestination to the destination and transmits route information socalculated to the vehicular navigation system. The vehicular navigationsystem displays the route from the current point to the peripheral pointto the destination that it searched and the route from the peripheralpoint to the final destination to the destination that it received fromthe information center.

Incidentally, in a case where the information center calculates arecommended route and provides an in-vehicle navigation center with therecommended route so calculated, a route on a map and points along theroutes need to be transmitted. However, as inevitable in the case ofscale maps, digital map databases contain errors attributed to differentmap manufacturers. In order to absorb such errors in the digital mapdatabases, in conventional traffic information providing systems such asa VICS system, in order that even in the event that errors exist amongthe respective maps, a road can be recognized as the same road, nodenumbers (VICS node numbers) are defined for nodes such as intersectionsand link numbers (VICS link numbers) are defined for roads betweennodes, so that object points for traffic information are represented bythe link numbers and node numbers so defined. Information on the nodenumbers and link numbers is retained in the respective map databases, avehicular navigation system which complies with VICS can identify anobject route or position for traffic information based on the linknumbers and node numbers contained in the VICS information, irrespectiveof the type of the map database installed therein.

When also transmitting a route to a destination, by using these linknumbers, the route can be transmitted in the form of route informationin which link numbers for links from an starting point to an endingpoint.

However, node numbers and link numbers defined for the road network needto be renumbered with new numbers, when new roads are built or theexisting roads are rerouted, and node numbers and link numbers assignedto the digital map data produced by the respective map manufacturersalso need to be renumbered in association with the renumbering. Sincebuilding of new roads and rerouting the existing roads continue forever, as long as the identifying method using node numbers and linknumbers continues to be taken, the digital map databases need to bemaintained for ever spending lots of man-hours and money, and if anynegligence of the maintenance, no accurate road information can betransmitted.

In order to improve these points, a patent document No. 2(JP-A-2001-66146) proposes a digital map positional informationtransmitting method in which a transmission side which transmits roadsegments transmits latitude-longitude information in which latitudes andlongitudes at a plurality of points along a road segment are arrangedsequentially, and a reception side which has received the informationperforms a map matching to identify the road segment on its map.

However, in the method for transmitting a route by transmittinglatitude-longitude information on a plurality of points along the route,while many points have to be set along the route so that the receptionside can reproduce the true shape of the route in order to prevent anerroneous matching on the reception side, when the number of pointsalong the route is increased, the data volume of data to be transmittedis increased, leading to problems that costs for transmitting routeinformation are accumulated and, in addition, that processing loads onthe transmission side and the reception side are increased.

DISCLOSURE OF THE INVENTION

The invention was made to solve the conventional problems and an objectthereof is to provide a route information transmission method fortransmitting a recommended route or a guided route to a reception sideaccurately and with as small a data volume as possible and a system forperforming the method.

Then, according to the invention, there is provided a route informationtransmitting method which is characterized in that a transmitting sideprovides a receiving side which requests route information withcompressed data obtained by arithmetically processing positional data ofa plurality of points aligned along a route so as to convert thepositional data into statistically biased data and variable lengthcoding the statistically biased data so converted, and in that thereceiving side identifies the route by decoding the compressed data soas to restore the positional data.

Due to this, the route information can be transmitted accurately with asmall volume of data.

In addition, according to the invention, there is provided a routeinformation providing apparatus which is characterized by comprising atransmitting means for transmitting a request for the provision of routeinformation, a receiving means for receiving compressed data providedand a means for decoding the compressed data so as to restore positionaldata of a plurality of point aligned along a route.

Due to this, the route information receiving apparatus can identify theroute accurately from the information of a small volume of data.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram illustrating the configuration of arecommended route providing system according to a first embodiment ofthe invention;

FIG. 2 is an exemplary drawing illustrating the recommended routeproviding system according to the first embodiment of the invention;

FIG. 3 is a data configuration drawing of recommended route informationtransmitted by the recommended route providing system according to thefirst embodiment of the invention;

FIG. 4 shows drawings explaining a variable length coding by a routeinformation transmission method according to the first embodiment of theinvention;

FIG. 5 is a drawing showing a code table used in the route informationtransmission method according to the first embodiment of the invention;

FIG. 6 is a block diagram illustrating the configuration of a runningroute providing system according to a second embodiment;

FIG. 7 is an exemplary drawing illustrating the running route providingsystem according to the second embodiment of the invention; and

FIG. 8 is a data constitution drawing illustrating running routeinformation transmitted by the running route providing system accordingto the second embodiment of the invention.

In addition, reference numerals in the drawings denote respectively asbelow:

10: running route storing and transmitting device; 11: informationrequest range information receiving unit; 12: running route informationextracting unit; 13: running route information storage unit; 14: runningroute manual inputting unit; 15: running route compression encodingunit; 16: running route information transmitting unit; 20: running routeinformation utilizing device; 21: information request range transmittingunit; 22: information request range calculating unit; 23: running routeinformation receiving unit; 24: compressed data decoding unit; 25:digital map database; 26: map matching unit; 27: running routeinformation utilizing unit; 30: route calculating device; 31: startpoint and destination information receiving unit; 32: route calculatingunit; 33: traffic information collecting unit; 34: route informationcompression encoding unit; 35: route information transmitting unit; 40:route information utilizing device; 41: start point and destinationinformation receiving unit; 42: subject vehicle position calculatingunit; 43: destination information inputting unit; 44: route informationreceiving unit; 45: compressed data decoding unit; 46: map matchingunit; 47: digital map database; 48: route information utilizing unit;51: probe car; 52: probe car; 53: sensor; and 54 sensor.

BEST MODE FOR CARRYING OUT THE INVENTION

Embodiments of the invention will be described below by reference to thedrawings.

(First Embodiment)

In a first embodiment of the invention, a case will be described inwhich information on a recommended route to a destination istransmitted.

In a route information transmitting method according to the firstembodiment of the invention, sampling points are reset at intervals of aconstant distance along a recommended route (this being referred to asequidistant re-sampling), a compression encoding treatment is applied toa data string in which position data of the respective sampling pointsare aligned sequentially and compression encoded data are transmitted. Areceiving side which receives them restores the data string of theposition data of the sampling points to thereby identify the recommendedroute.

Furthermore, in order to identify the route information so received moreaccurately, an object road is identified on its own digital map data byperforming a matching with its own digital map data. In addition, whenalso performing a route guidance (voice guidance and enlarged display ofintersections and interchanges, deformed display), as has beendescribed, an object road needs to be identified on a digital mapdatabase held in its own device by performing a matching.

In the event that there exists no road corresponding to the receivedroute information on its own digital map database, assuming that theobject road is a newly opened road, a route guidance is performed.

The compression encoding of the data string of position data isperformed in the following order; {circle around (1)} Conversion of theposition data into a single variable, {circle around (2)} Conversion ofa value represented by the single variable into a statistically biasedvalue, and {circle around (3)} Variable length coding of the convertedvalue.

(1) Conversion of Position Data into Single Variable

FIG. 4A shows sampling points set along the recommended route in theequidistant re-sampling as PJ-1, PJ. The sampling point (PJ) canuniquely be identified in two dimensions of a distance L from theadjacent sampling point (PJ-1) and an angular component Θ, and assumingthat the distance is constant (L), the sampling point (PJ) can berepresented by one variable of only the angular component Θ from theadjacent sampling point (PJ-1). In FIG. 4A, as this angle Θ, an angle Θis shown which is represented by an absolute orientation whichdesignates the magnitude in a range of 0 to 360 degrees measuredclockwise from the orientation of true north (top on the map) which isregarded as 0 degree. Assuming that the x-y coordinates (latitude,longitude) of PJ-1 and PJ are (xj-1, yj-1) and (xj, yj), respectively,this angle Θj-1 can be calculated from the following equation:Θj-1=tan−1{(xj−xj-1)/(yj−yj-1)}

Consequently, the recommended route can be represented by a data stringof angular components of the respective sampling points by designatingthe constant distance L between the sampling points and latitude andlongitude of the sampling point (reference point) which constitutes astarting point or an ending point separately.

(2) Conversion of Single Variable Value into Statistically Biased Value

In order for a single variable value of each sampling point to become astatistically biased value which is suitable for variable length coding,as shown in FIG. 4B, the angular component of each sampling point isrepresented by a displacement difference from the angular component ofthe adjacent sampling point, that is, a deviation angle Θj. Thisdeviation angle Θj is calculated as:Θj=Θj−Θj-1In the event that the road is rectilinear, the deviation angle of eachsampling point focuses on the vicinity of 0 and becomes statisticallybiased data.

In addition, as shown in FIG. 4C, the angular component of the samplingpoint can be converted into statistically biased data by representingthe deviation angle θj of the sampling point PJ, to which attention isto be paid, by a difference value (deviation-angle estimated differencevalue) Δθj from a deviation angle estimated value Sj (statisticallyestimated value) of the sampling point PJ which is estimated usingdeviation angles θj-1, θj-2, . . . of the previous sampling points PJ-1,PJ-2, . . . . The statistically estimated value Sj can be defined as,for example:Sj=θj-1;orSj=(θj-1+θj-2)/2In addition, Sj may be defined in terms of a weighted average ofdeviation angles at the n previous sampling points. The deviation-angleestimated difference value Δθj is calculated as:Δθj=θj−SjIn the event that the road curves at a constant curvature, adeviation-angle estimated difference value Δθ of each sampling pointfocuses on the vicinity of 0 and becomes statistically biased data.

FIG. 4D is a graph illustrating frequency at which data are generatedwhen the rectilinear recommended route is represented by the deviationangle θ and when the curved recommended route is represented by thedeviation-angle estimated difference value Δθ. The generation frequencyof θ and Δθ becomes maximum when θ=0° and is statistically biased.

(3) Variable Length Coding

Next, the value of the data string which is converted into thestatistically biased value is variable length coded. While the variablelength coding method includes many types of methods such as fixednumerical value compression method (0 compression or the like),Shannon-Fanno coding method, Huffman coding method, arithmetic codingmethod and lexicographic coding method, here a case will be described inwhich Huffman coding method, which is the commonest, is used.

In this variable length coding, more frequently generated data are codedby bits in a smaller number and less frequently generated data are codedby bits in a greater number, so that the total data volume is reduced. Arelationship between the data and codes are defined in a code table.

Now, assume that the arrangement of Δθs at sampling points along therecommended route which are represented in a unit of 1° is as follows:

“0_(—)0_(—)—2_(—)0_(—)0_(—)+1_(—)0_(—)0_(—)—1_(—)0_(—)+5_(—)0_(—)0_(—)0_(—)+1_(—)0”

A case will be described where a code table shown in FIG. 5 in whichvariable length coding and run length coding are combined is used inorder to code the data string. The code table regulates such that Δθwhich is in the range of −1° to +1° is regarded as 0° and is thenrepresented by a code 0, in a case where 0° occurs continuously fivetimes, it is represented by a code 100, and in a case where 0° occurscontinuously ten times, it is represented by a code 1101. In addition,Δθ which is in the range of +/−2° to 4° is regarded as +/−3° and when itis positive, Δθ is then represented by adding an additional bit 0 to acode 1110, whereas when it is negative, Δθ is then represented by addingan additional bit 1 to the code 1110, Δθ which is in the range of +/−5°to 7° is regarded as +/−6° and is then represented by adding anadditional bit denoting positive or negative to a code 111100, and Δθwhich is in the range of +/−8° to 10° is regarded as +/−9° and is thenrepresented by adding an additional bit denoting positive or negative toa code 111101.

Due to this, the data string is coded as follows:

“0_(—)0_(—)11101_(—)100_(—)0_(—)0_(—)1111000_(—)100”→“0011101100001111000100”

The receiving side which has received the data restores the data stringof Δθs using the same code table as that used in coding and reproducesthe position data of the sampling points by performing an oppositeprocess to that implemented on a transmitting side.

FIG. 2 exemplarily illustrates a system for providing recommended routeinformation using this route information transmitting method, andadditionally, FIG. 1 illustrates the configuration of the system in ablock diagram.

A route calculating device 30 for providing route information includes astart point and destination information receiving unit 31 for receivinginformation on start point and a destination from a route informationutilizing device 40 such as a vehicular navigation system, a trafficinformation collecting unit 33 for collecting information fromultrasonic vehicle sensors and image sensors which are placed along eachroad or various types of sensors 53, 54 such as probe cars functioningas running traffic information collecting sensors and also collectinginformation on an unexpected event such as an accident which is enteredmanually, a route calculating unit 32 for calculating a recommendedroute from the start point to the destination and a required time (atraveling time) to cover the route while referring to the trafficinformation collected by the traffic information collecting unit 33, aroute information compression encoding unit 34 for compression encodingthe information on the recommended route, and a route informationtransmitting unit 35 for transmitting data of the compression encodedrecommended route and traveling time information to the routeinformation utilizing device 40.

Then, the route information utilizing device 40 includes a subjectvehicle position calculating unit 42 for detecting the position of thesubject vehicle using a GPS function or the like, a destinationinformation inputting unit 43 for inputting a destination, a start anddestinations information transmitting unit 41 for transmittinginformation on the current point and the destination to the routecalculating device 30, a route information receiving unit 44 forreceiving recommended route information from the route calculatingdevice 30, a compressed data decoding unit 45 for decoding thecompression encoded data, a digital map database 47, a map matching unit46 for performing a map matching of the position data of the decodedrecommended route with digital map data to thereby identify therecommended route on a digital map and a route information utilizingunit 48 for displaying the recommended route.

In this system, when the user enters a traveling destination from thedestination information inputting unit 43 of the route informationutilizing device 40, requesting the provision of route information tothe destination, the route information utilizing device 40 transmits thecurrent point detected by the subject vehicle position calculating unit42 and the destination inputted from the destination informationinputting unit 43 to the route calculating device 30.

Then, in the route calculating device 30, vehicle detection informationtaken by the ultrasonic vehicle sensors and image sensors which areplaced along each road is collected to the traffic informationcollecting unit, and, in addition, information on the speed measured bythe running probe car is sent to the traffic information collecting unit33 via cellular phones and beacons. In addition, information on trafficaccidents or road constructions which are entered manually is alsocollected to the traffic information collecting unit 33.

When receiving the information on the current point and the destinationwhich was sent from the route information utilizing device 40, the routecalculating unit 32 of the route calculating device 30 refers to thetraffic information collected by the traffic information collecting unit33 and then calculates several recommended routes and traveling timeswhich allow the user to reach from the current point to the destinationin a short period of time. The route information compress encoding unit34 performs an equidistant re-sampling as to the recommended routecalculated by the route calculating unit 32 so as to variable lengthcode a data string of the position data of the sampling points using theaforesaid method. Information on the compression encoded data stringregarding the recommended route and the traveling time is sent from theroute information transmitting unit 35 to the route informationutilizing device 40.

FIG. 3 illustrates the data configuration of the recommended routeinformation sent from the route calculating device 30. Here, in coding,either deviation angles or deviation-angle estimated difference valuesare used as coding parameters, or, information on the constant distanceL set in the equidistance re-sampling, identification numbers in thecode table and latitude and longitude of the reference point (startpoint, destination) is described, the number of recommended routes thatare provided is described as the number of routes provided, andfurthermore, the route shape is described which is represented by thetraveling time of each recommended route and the data string of variablelength coded data.

In the route information utilizing device 40, which has received therecommended route information, the compressed data decoding unit 45decodes the data string of coded route shape data and restores theposition data of the sampling points aligned along the recommendedroute. As this occurs, the compressed data decoding unit 45 performs thedecoding of the route shape data using a code table of an identificationnumber designated by the coding parameters among a plurality of codetables given in advance from the route calculating device 30 and held.

The map matching unit 46 obtains points along the road which correspondto the sampling points on the recommended route in a known map matchingmethod using map data of the digital map database 47 and identifies therecommended route on the digital map.

The route information utilizing unit 48 displays the recommended routeon a screen and guides a traveling direction of the vehicle along therecommended route via voice or enlarged views of intersections andinterchanges.

Thus, in this system, since the shape data of the recommended route arecoded and transmitted, the volume of data transmitted becomes small. Inaddition, the receiving side can identify the recommended routeaccurately through map matching.

In the route information transmitting method described in the patentdocument No. 1, while the information sent to the vehicular navigationsystem from the information center (the route calculating device) withthe route from the current point to the final destination beingcalculated thereby is limited only to the route information from theperipheral point to the final destination to the destination, in theroute information sending method according to the first embodiment ofthe invention, since the volume of data that are transmitted is small,the route information from the current point to the final destinationcan be transmitted without causing the transmitting side and thereceiving side to bear a great load.

Note that while in this embodiment, the case has been described in whichthe recommended route is re-sampled equidistantly, and the angularcomponents of the position data at the sampling points are convertedinto the statistically biased value for the variable length coding, itis possible to perform the variable length coding by setting a samplingpoint along the recommended route in such a manner that the deviationangle becomes constant and converting the distance Lj to the adjacentsampling point into a statistically biased value (for example, adistance estimated difference value ΔLj is obtained from ΔLj=Lj−Sj bydefining Sj=Lj-1). In addition, it maybe possible to perform thevariable length coding by setting nodes and interpolating points (pointsset on the map to represent the shape of the route) along therecommended route as sampling points and converting both angularcomponent θj and distance component Lj, which are made to function asvariables, into statistically biased values.

(Second Embodiment)

In a second embodiment of the invention, a system for providinginformation indicating the traveling path of other vehicles will bedescribed.

For example, a running storing and transmitting device 10 includes aninformation request range information receiving unit 11 for receivinginformation designating an area from a running route informationutilizing device 20 such as a vehicular navigation system and a personalcomputer, a running route manual inputting unit 14 for manuallyinputting a running route, a running route information storing unit 13for storing running routes sent from respective probe cars 51, 52 orrunning routes inputted from the running route inputting unit 14, arunning route information extracting unit 12 for extracting a runningroute within an information request range (area or date and time band)designated by the running route information utilizing device 20 amongthe running routes stored in the running route information storing unit13, a running route compression encoding unit 15 for compressionencoding the running route so extracted and a running route informationtransmitting unit 16 for transmitting the compression encoded runningroute to the running route information utilizing device 20.

In addition, the running route information utilizing device 20 includesan information request range calculating unit 22 for setting aninformation request range, an information request range transmittingunit 21 for transmitting the information request range so set to therunning route storing and transmitting device 10, a running routeinformation receiving unit 23 for receiving running route informationfrom the running route storing and transmitting device 10, a compresseddata decoding unit 24 for decoding data of a compression encoded runningroute, a database of digital maps, a map matching unit 26 for performinga map matching of position data of the running route so decoded with thedigital map data to thereby identify the running route on the digitalmap, and a running route information utilizing unit 27 for displayingthe running route.

In this system, the running route information utilizing device 20 suchas a vehicular navigation system and a personal computer determines aninformation request range, that is, the type of a day (week days,holidays and the like) and a time band (the peak hours of traffic on themorning roads, the peak hours of traffic on the evening roads, slackhours on night roads) and transmits the information request range sodetermined to the running route storing and transmitting device 10.

Then, in the running route storing and transmitting device 10, travelingpath of the probe cars 51, 52 are transmitted thereto via cellularphones and beacons or stored on a storage medium such as a flexible diskfor input thereinto, whereby the traveling path so transmitted orinputted are stored in the running route information storing unit 13. Inaddition, a running route inputted from the running route manualinputting unit 14 is also stored in the running route informationstoring unit 13.

The running route extracting unit 12 extracts a running route fallingwithin the information request range from running routes stored in therunning route information storing unit 13. As in the case with the firstembodiment, the running route compression encoding unit 15 performs anequidistance re-sampling on the running route so extracted so as tovariable length code a data string of position data of the samplingpoint by the aforesaid method. The running route information socompressed is transmitted from the running route informationtransmitting unit 16 to the running route information utilizing device20 which requested the provision of the information.

FIG. 8 illustrates the constitution of data of route information sentfrom the route calculating device 30. Here, together with encodingparameters and the number of locus data to be provided, the profile (thetime of the day of the month in the year when the running was carriedout, traveling time and the like) of each traveling path and the shapeof the running route represented by the data string of variable lengthencoded data are described.

In the running route information utilizing device 20, the compresseddata decoding unit 24 decodes the encoded data string of running routeshapes so as to restore the position data of the sampling points alignedalong the running route. As this occurs, the compressed data decodingunit 24 decodes the data of the shape of the running route using a codetable of identification numbers which is designated by the codingparameters from a plurality of code tables given in advance by therunning route storing and transmitting device 10 and held therein.

The map matching unit 26 obtains positions along the road whichcorrespond to the sampling points along the running route by a known mapmatching method, using the map data of the digital map database so as toidentify the running route on the digital map.

The running route information utilizing unit 27 displays the runningroute on the screen.

Thus, in this system, by compression encoding the information oftraveling path requested by the receiving side, the running routeinformation can be transmitted in a small volume of transmission data.In particular, in a case where a taxi driven by a professional driver ora vehicle driven by a person who lives in the vicinity of a target placeis designated as a probe car, so that traveling path of the taxi ofvehicle are stored, running route information can be provided which isfar more valuable as route information than running route informationthat would be obtained through driving of a vehicle by a driver who isnot familiar with the target place.

Thus, while the invention has been described in detail or by referenceto the specific embodiments, it is clear to those skilled in the artthat various changes and/or modifications can be made thereto withoutdeparting from the sprit and scope of the invention.

The patent application of this invention is such as to be based on theJapanese Patent Application (No. 20030125340) and the contents thereofare incorporated herein by reference.

INDUSTRIAL APPLICABILITY

As is clear from the description that has been made heretofore, theroute information transmitting method according to the invention cantransmit the route information accurately in a small volume of data.

In addition, the device according to the invention can transmit orreceive information effective in supporting the driving of a vehiclesuch as a route to a destination and traveling path of the past drivingby the route information transmitting method.

1. A route information transmitting method comprising: arithmeticallyprocessing position data of a plurality of points aligned along a routeso as to convert the position data into statistically biased data andvariable length coding the statistically biased data to obtaincompressed data at the transmitting side; transmitting the compresseddata from the transmitting side to a receiving side; and identifies theroute by decoding the compressed data so as to restore the position dataat the receiving side.
 2. The route information transmitting methodaccording to claim 1, further comprising: requesting, from the receivingside to the transmitting side, route information to the destination byindicating a current point and a destination; and calculating the routeto the destination and obtaining the compressed data on the basis of thecalculated route at the transmitting side.
 3. The route informationtransmitting method according to claim 1 further comprising: requesting,from the receiving side to the transmitting side, information on atraveling path with designating a range; and extracing a traveling pathwhich falls within the range from past traveling path information storedin the transmitting side and obtaining the compressed data on the basisof the extracted traveling path at the transmitting side.
 4. The routeinformation transmitting method according to claim 1, wherein thetransmitting side obtains the compressed data by implementing anequidistance re-sampling on the route, representing position data of asampling point by a deviation angle and variable length coding thedeviation angle.
 5. The route information transmitting method accordingto claim 1, wherein the transmitting side obtains the compressed data byimplementing an equidistance re-sampling on the route, representingposition data of a sampling point by a deviation-angle estimateddifference value and variable length coding the deviation-angleestimated difference value.
 6. The route information transmitting methodaccording to claim 1 further comprising: performing a matching withdigital map data held in a device of the receiving side using therestored position data so as to identify an object road on the digitalmap data at the receiving side.
 7. A route information providingapparatus comprising: a receiver the receives a request for informationon a route; an encoder that arithmetically processes position data of aplurality of points aligned along a route so as to convert the positiondata into statistically biased data and variable length codes thestatistically biased data to obtain compressed data transmitter thattransmits the compressed data.
 8. The route information providingapparatus according to claim 7 further comprising: route calculator thatcalculates a route to a destination based on information on a currentpoint and the destination which is received by the receiver, wherein theencoder produces the compressed data based on the route calculated bythe route calculator.
 9. The route information providing apparatusaccording to claim 7 further comprising: storage that receives andstores information on a traveling path; and traveling route informationextractor for extracting a traveling path which falls within adesignated range received by the receiver from traveling path stored inthe storage, wherein the encoder produces the compressed data based onthe traveling path extracted by the traveling route extractor.
 10. Aroute information receiving apparatus comprising: transmitter thatrequests information on a route; receiver that receives compressed datain which position data of a plurality of points aligned along the routeis compressed; and a compressed data decoder that restores the positiondata of the plurality of points by decoding the compressed data.
 11. Theroute information receiving apparatus according to claim 10, whereininformation on a current point and a destination is transmitted from thetransmitter, a matching with a digital map is performed using theposition data restored from the compressed data, and the route isidentified on the digital map, so that a route from the current point tothe destination is identified.
 12. A route information receivingapparatus as set forth in claim 10, wherein information designating arange is transmitted from the transmitter, a matching with a digital mapis performed using the position data restored from the compressed data,and the route is identified on the digital map, so that a traveling pathfalling within the range is identified.
 13. A route informationreceiving apparatus according to claim 10, further comprising: a mapmatching unit that performs a matching with a digital map using theposition data restored by the compressed data decoder so as to identifythe route on the digital map.
 14. A route information receivingapparatus according to claim 13 wherein, the transmitter transmitsinformation on a current point and a destination, and the map matchingunit identifies a route from the current point to the destination.
 15. Aroute information receiving apparatus according to claim 13 wherein thetransmitter transmits information designating a range, and the mapmatching unit identifies a traveling path falling within the range.